March 30, 1871 | 
NATURE 
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the disc ; this phantom wheel appears motionless if the 
periods exactly coincide, but if they do not, it slowly re- 
volves in one direction or the other. {t is obvious that 
this affords an easy method of counting the vibrations of 
the flame. With a sixteen inch tube I thus found the 
number of complete vibrations per second to be about 
453- 
When the disc is rotated in front of a vertical vibrating 
wire, the eye being placed where the slits pass in a hori- 
zontal position, the interval of the slits passing being 
equal to a complete vibration of the wire, the wire appears 
thrown into undulations and motionless. If the periods 
do not exactly coincide, the undulations travel up or down 
the wire. If the velocity of the disc be doubled, or trebled, 
the apparent number of wires is increased in like propor- 
tion ; and if it be regarded by the two eyes placed where 
the slits do not pass in a horizontal position, they assume 
the form of spirals, which appear to revolve around each 
other in an extremely beautiful and illusive manner. In 
the above cases I have supposed the wire to be twanged in 
the centre, in which case the undulations are beautifully 
symmetrical curves, and represent a pure note. If, how- 
ever, the wire be twanged near to one end, the change in 
the gzalzty of the note is manifest, the irregularity of the 
curves showing the presence of minor undulations super- 
imposed upon the primary one. The best wire for this’ 
purpose is a fine spiral one, as it gives vibrations of great 
amplitude, and of Jong continuance. A vibrating steel 
rod also appears thrown into the same undulations. 
CHARLES J. WATSON 

THE ACTION OF FLUORSPAR ON DIFFERENT 
QUALITIES OF CAST IRON 
[NX my articles contributed to NATURE(No. 57, p. 94, and No. 
64, p. 233), I have given descriptions of my process of ap- 
plying fluorspar combined with oxides, and fluorspar combined 
with oxides containing titanium, to ordinary cast iron, 
It is reported that attempts have been made to apply fluorspar 
alone to ordinary cast iron by eminent chemists in the laboratory, 
but the results have been of a negative character. These reports 
have been corroborated by my own experiments. I have dis- 
covered,* however, that although fluorspar has no effect when 
used alone in treating ordinary cast iron, it will act energetically 
upon cast iron containing titanium. The titaniferous cast iron 
was made at Glassdale Furnaces, near Whitby, by melting 
Cleveland white pig iron in a cupola in admixture with Norwe- 
gian titanic iron ore, and blast furnace cinder as a flux. This 
metal was treated here in the laboratory by being melted upon 
powdered fluorspar. The resulting metal was found to be 
wrought iron. 
These results may be obtained in any suitable vessel, furnace, 
apparatus, or process; the only conditions necessary to be 
observed are, that the metal be maintained in the fluid state, and 
the fluorspar placed so as to act upon the metal from the under 
side upwards, or placed in admixture with it, and that when 
apparatus is used having silicious linings, the silicious linings be 
protected with sheet or cast iron placed upon the silicious lining 
before the fluorspar and iron to be treated are charged into the 
vessels. No labour is necessary, except that of “balling” 
the metal, and removing it from the apparatus. 
The results given by this experiment go to prove that by this 
process superior qualities of wiought iron, which will be purer 
than the highest standard brands of wrought iron, may be pro- 
duced from the English Cleveland pig iron, which contains, 
according to the best metallurgical authorities, from 1°25 to 1°38 
per cent. of phosphorus. . ; 
One ton of Clevelund pig iron was melted in a cupola with 
7 cwts. of Norwegian titanic iron ore, containing, by analysis, 
about 40 per cent. of titanic acid. The resulting metal was 
titaniferous cast iron, analysing :— 
Titanium. 58 Garces +: cee keeh5c 
Siconae 1: seeks) REEOLAD 
Phosphorus . . . . ~ 074604 
Snlphanss sie mists- oak o20 
Garbona: setts. te '8* 8 2082 
* Patent No, 318, Feb. 3, 1870 

Hence it appears that the iron, by being re-melted with tita- 
niferous iron ore, took up 1°25 per cent. of titanium, and lost 
0°90 per cent. of phosphorus, and 1°75 per cent. of carbon. It 
is obvious that the metal in this condition is not available for any 
purpose without subsequent treatment, as it contains about as 
great an amount of impurities as it did before treatment. 
The advantages gained by re-melting the pig iron with tita- 
niferous iron ore are, a reduction of the amount of phosphorus 
and carbon, and the alloying of the metal with titanium, which 
facilitates the removal of the impurities ‘in the subsequent treat- 
ment. 
The above described titaniferous cast iron was remelted upon 
fluorspar, and about 30 minutes after the iron melted, or in about 
an hour after they were both charged, the iron was found to be 
malleable iron ; the button analysing as follows :— 
ST faMiU Mer ee ee ta O25 
Gilicoritae secs Ree oe UNOone 
Phosphorus). 5! 87) 9) so*1300 
Sulphur 4.00% Gale, "oro0z0 
(Carboneamttcs st) ieee meme tALCeS 
When worked on a larger scale, so as to produce blooms that 
can be worked into merchantable shapes, the finished results 
will show less phosphorus and sulphur than the above analysis, 
as it is well known to metallurgists, by the experiments of Messrs. 
Calvert and Johnson, published in full in Kerl’s “ Metallurgy,” 
vol. ii., ‘* Copper and [ron,” 1869, that 0’022 per cent. of phos- 
phorus, and 0040 per cent. of sulphur, are removed in working 
blooms into finished iron. 
It will be seen that the action of the fluorspar removed 
4°9662 per cent. of the impurities contained; and _ that 
the resulting metal contains less impurities in amount than the 
highest standard qualities of wrought iron, The explanation of 
these effects I leave to chemical investigators, without hazarding 
an opinion which might be erroneous, and therefore disadvan- 
tageous to me, 
JAMES HENDERSON 

MR. WALLACE’S ANNIVERSARY ADDRESS* 
Ne CONSIDERABLE portion of this Address is devoted to a 
discussion of the facts of distribution of beetles, as presented 
by Mr. Wollaston in his great work, the ‘‘ Insecta Maderensia,” 
with special reference to the views advocated by Mr. Andrew 
Murray, in his paper on the Geographical Distribution of Beetles. 
After touching on the various methods by which insects are 
known to be distributed, and mentioning several of the instances 
in which they have been captured some hundreds of miles from 
land, it is concluded that, in opposition to the view held by Mr. 
Murray, there is no reason to believe that the Atlantic islands 
owe their Coleoptera to a former land connection with the con- 
tinent, more especially as there is such strong evidence against 
that view in the total absence of mammals and reptiles. Mr. 
Wailace then applies Mr. Wollaston’s facts to a detailed test of 
these views; and, as this portion of the paper is of general 
interest to naturalists, we give it at length :— 
The most novel and striking facts brought out by Mr. Wol- 
laston’s researches in Madeira are, as is well known (1) the 
affinity with the Mediterranean fauna ; (2) the total absence of 
certain large divisions of Coleoptera abundant in that fauna ; 
(3) the number of new and peculiar species and of new and 
anomalous genera ; and (4) the unexampled preponderance of 
apterous species. Now accepting, as Mr. Murray does, the 
theory of slow change of forms by natural causes, we may take 
the first and third of these facts as proving that the origin of the 
Madeiran fauna is of very ancient date. Let us see, therefore, 
how the second and the fourth set of facts bear upon the mode of 
its origin, whether by a land-connection with Europe or by trans- 
mission across the sea. It will be convenient to take first the 
facts presented by the apterous or winged condition of the 
species. 
This striking peculiarity consists, either in species being 
apterous in Madeira which are winged elsewhere, or in genera 
which are usually winged consisting of only apterous species in 
Madeira, or lastly, in the presence of endemic apterous genera, 
some of which have winged allies, while others belong to groups 
* An Address read at the Anniversary Meeting of the Entomological 
Society of London, on the 23rd of January, 1871, by Alfred R. Wallace, 
F.Z,S., F.R.G.S., President. 
